Field of the Disclosure
This application relates to an airflow control into an internal combustion engine. More particularly, the application relates to performing an optimal control of an internal combustion engine using an explicit model predictive controller in combination with a switch gain scheduler.
Description of the Related Art
Air flow control of an internal combustion engine is an important strategy to increase engine performance and fuel economy. This is particularly true with diesel engines. Traditionally, an air flow control strategy is developed using a proportional (P), integral (I), and differential (D) control design. PID control design is focused on nominal engine operating conditions and consequently does not perform effectively under off-nominal conditions. PID is a well-known simple control approach utilized for single input single output (SISO) systems. PID approaches have been extended to multiple-input multiple output (MIMO) systems; however more advanced control techniques are able to deliver better performance, e.g. Model Predictive Controller (MPC). MPCs are popular in the process industry such as in chemical processing technologies and are currently being adopted with limited use in the automotive industry. Internal combustion engines operate under different conditions (e.g., high speed or load vs low speed or load) during their use. Each engine operating condition has an air flow dynamic that necessitates design of multiple controllers. Design and use of multiple controllers trigger problems related to the limited memory of an engine control unit (ECU) and the cost of controller calibration.